Outdoor unit for air conditioning device

ABSTRACT

A spray nozzle of an outdoor unit is provided with: an air guide portion through which air flows; a water guide portion through which water flows and which causes the air flowing through the air guide portion to flow into water to form water containing a large number of bubbles; and a spray portion that is located downstream of the water guide portion in a direction of water flow and sprays, to the outside, the water containing a large number of bubbles which is formed in the water guide portion.

TECHNICAL FIELD

The present invention relates to an outdoor unit for an air conditioningdevice.

BACKGROUND ART

There has conventionally been known an outdoor unit for an airconditioning device that has a spray device for auxiliary cooling a heatexchanger by spraying water from a spray nozzle to the heat exchanger.Cooling the heat exchanger by means of the sprayed water in this outdoorunit can effectively reduce the power (power consumption) required bythe air conditioning device. In this type of air conditioning device,unfortunately, droplets of the water adhering to the surface of the heatexchanger often leads to corrosion of the heat exchanger.

Patent Document 1 discloses an outdoor unit provided with a fine mistgenerating nozzle. This fine mist generating nozzle is located on theupstream side of a heat exchanger and away therefrom, and generates finemist having a particle diameter of 10 μm or less by injecting air andwater simultaneously. Patent Document 1 describes that the fine mistinjected from the fine mist generating nozzle evaporates prior toreaching the heat exchanger, preventing adherence of the droplets to theheat exchanger.

-   Patent Document 1: Japanese Patent Application Publication No.    2008-128500

However, a spray nozzle that injects air and water simultaneously fromits spray hole is a conventional two-fluid nozzle that creates finedroplets by adding shear force to the water at the pressure of the air.For this reason, the spray nozzle requires large power for the purposeof injecting air at high speeds. In such a case, the power reductioneffect of the entire air conditioning device might not be accomplishedadequately.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an outdoor unit that iscapable of reducing the power of the entire air conditioning devicewhile preventing corrosion of a heat exchanger.

An outdoor unit for an air conditioning device according to the presentinvention has a heat exchanger and a spray nozzle for spraying water toair flowing toward the heat exchanger. The spray nozzle is provided withan air guide portion through which the air flows, a water guide portionthrough which water flows and in which the air flowing through the airguide portion flows into the water to form water which contains a largenumber of bubbles, and a spray portion which is located downstream ofthe water guide portion in a direction of water flow and which sprays tothe outside the water formed in the water guide portion and containing alarge number of bubbles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an outdoor unit according to afirst embodiment of the present invention.

FIG. 2 is a perspective view showing how a heat exchanger and spraynozzles are arranged in the outdoor unit.

FIG. 3 is a cross-sectional diagram of one of the spray nozzles.

FIG. 4 is a cross-sectional diagram of a spray nozzle of an outdoor unitaccording to a second embodiment of the present invention.

FIG. 5 is a cross-sectional diagram of a spray nozzle of an outdoor unitaccording to a third embodiment of the present invention.

FIG. 6A is a perspective view showing an air guide pipe of the spraynozzle according to the third embodiment, FIG. 6B a perspective viewshowing modification 1 of the air guide pipe, and FIG. 6C a perspectiveview showing modification 2 of the air guide pipe.

FIG. 7 is a schematic diagram showing an outdoor unit according toanother embodiment of the present invention.

FIG. 8 is a perspective view showing how a heat exchanger and spraynozzles are arranged in the outdoor unit.

FIG. 9 is a schematic diagram for explaining an example of thearrangement of spray nozzles in relation to the heat exchanger.

FIG. 10 is a schematic diagram showing an outdoor unit according to yetanother embodiment of the present invention.

FIG. 11 is a diagram for explaining the relationship between adistribution of wind velocity of air flowing toward a heat exchanger inthe outdoor unit and the distance between a spray nozzle and each ofvarious sections of the heat exchanger.

FIG. 12A is a schematic diagram for explaining modification 1 of acharging mechanism, and FIG. 12B an enlarged perspective view forexplaining a spray nozzle and an induction electrode.

FIG. 13 is a schematic diagram for explaining modification 2 of thecharging mechanism.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

An outdoor unit according to a first embodiment of the present inventionis now described hereinafter with reference to the drawings.

An outdoor unit 11 according to the first embodiment is used in an airconditioning device. The air conditioning device has the outdoor unit 11shown in FIG. 1, an indoor unit which is not shown, and a refrigerantpipe section, not shown, which connects the outdoor unit 11 and theindoor unit to each other. As shown in FIG. 1, the outdoor unit 11 has acase 12, a heat exchanger 13, a fan 14, a compressor 15, a spray device20, an outside air temperature sensor 18, a controller 16 and the like.The heat exchanger 13, the fan 14, the compressor 15, and the controller16 are disposed inside the case 12. The fan 14, the compressor 15, andthe spray device 20 are controlled by the controller 16. The compressor15 and the heat exchanger 13 are provided in a refrigerant circuit ofthe air conditioning device.

Examples of the heat exchanger 13 include, but are not limited to, across fin coil-type heat exchanger. The cross fin coil-type heatexchanger has heat-transfer pipes and a large number of plate finsthrough which the heat-transfer pipes penetrate. A refrigerant flowsinside the heat-transfer pipes, and outside air flows between the platefins. As a result, heat exchange between the refrigerant and the outsideair takes place.

As shown in FIG. 2, the heat exchanger 13 extends upward from a bottompanel of the case 12 and formed in substantially a U-shape as planarlyviewed. In other words, the heat exchanger 13 is provided upright withrespect to an installation surface (horizontal surface) of the outdoorunit 11. Of the four side panels of the case 12, the three side panelsfacing the heat exchanger 13 are each provided with an air inlet, notshown, which draws in outside air into the case 12. The top panel of thecase 12 is provided with an air outlet 17 for blowing the air of thecase 12 to the outside.

A centrifugal fan, an axial fan, a diagonal flow fan or the like can beused as the fan 14. The fan 14 has an impeller 14 a and a motor, notshown, which rotates the impeller 14 a. The fan 14 is disposed inward ofthe heat exchanger 13 in a horizontal direction in the outdoor unit 11and above the heat exchanger 13. More specifically, the fan 14 isprovided in an upper part of the case 12, as shown in FIG. 1, and isdisposed immediately below the air outlet 17 shown in FIG. 2. The fan 14emits upward, from the outdoor unit 11 (the case 12) to the outside, airthat flew into the outdoor unit 11 (the case 12) and was subjected toheat exchange by the heat exchanger 13. In other words, the fan 14 islocated downstream of the heat exchanger 13 in a direction of airflow.

When the air conditioning device is running, the compressor 15 receivespower, which consequently allows the refrigerant to circulate in therefrigerant circuit between the outdoor unit 11 and the indoor unit, andat the same time power is applied to the motor of the fan 14 to rotatethe impeller 14 a, thereby drawing in outside air through the air inletinto the case 12. Subsequent to heat exchange between the outside airdrawn into the case 12 and the refrigerant in the heat exchanger 13 asdescribed above, the outside air is blown to the outside of the case 12via the air outlet 17. More specifically, during, for example, a coolingoperation of the air conditioning device, heat exchange takes placebetween the outside air drawn into the case 12 and the high-temperature,high-pressure refrigerant via the heat-transfer pipe of the heatexchanger 13 functioning as a condenser, the refrigerant flowing throughthe heat-transfer pipe. In other words, the outside air cools theheat-transfer pipe of the heat exchanger 13 and the refrigerant. As aresult, the refrigerant flowing through the heat-transfer pipe is cooledand condensed.

The spray device 20 is described next. The spray device 20 is capable ofcooling the outside air flowing toward the heat exchanger 13 during thecooling operation. In other words, the spray device 20 lowers thetemperature of the outside air flowing toward the heat exchanger 13. Inthis manner, the effect of cooling the heat-transfer pipe of the heatexchanger 13 and the refrigerant can be enhanced. The spray device 20can therefore improve the cooling performance of the air conditioningdevice by auxiliary cooling the heat exchanger 13 and the refrigerant.

As shown in FIGS. 1 to 3, the spray device 20 has a plurality of spraynozzles 21, a water supply mechanism 60, an air supply mechanism 70, anda charging mechanism 80 as a charger.

The plurality of spray nozzles 21 are each supported by a supportingmember, not shown, which is provided separately on each side panel ofthe case 12 or in the case 12. Each of the spray nozzles 21 is locatedupstream of the heat exchanger 13 in a direction of an air stream whichis formed as the impeller 14 a of the fan 14 rotates. In the presentembodiment, each of the spray nozzles 21 is disposed on the outside ofand above the heat exchanger 13 in the outdoor unit 11, in such a manneras to spray droplets (water drops, in the present embodiment) downward.In other words, each of the spray nozzles 21 is disposed such that anaxial direction thereof is substantially perpendicular to the directionof outside air (the air) flowing substantially horizontally toward theheat exchanger 13. Water drops that are sprayed from each of the spraynozzles 21 are spread radially downward and moved toward the heatexchanger 13 by the flow of air. All or most of the water drops vaporizeprior to reaching the heat exchanger 13.

Because each of the spray nozzles 21 sprays water drops downward, eventhose large water drops that do not vaporize quickly are droppeddownward (onto the installation surface of the outdoor unit 11 or thelike) across the flow of outside air by the force of the downward spraymotion and gravity added to these water drops. This can preventadherence of the large water drops to the heat exchanger 13, whereby theheat exchanger 13 is prevented from being wet.

As shown in FIG. 2, the plurality of spray nozzles 21 are disposedhorizontally at intervals on three side panels 12 a, 12 b, 12 c facingthe heat exchanger 13 so as to provide the cooling effect of the spraydevice 20 to substantially the entire heat exchanger 13. Specifically,the plurality of nozzles 21 are disposed horizontally at an interval of,for example, several tens of centimeters based on a range in which thewater drops from each spray nozzle 21 are spread, i.e., a range in whichthe outside air flowing toward the heat exchanger 13 is cooled by eachspray nozzle 21.

The present embodiment illustrates a case in which the range in whichthe water drops from each spray nozzle 21 are spread (the horizontalrange) is, for example, approximately 50 cm, the width of the side panel12 a approximately, for example, 100 cm, and the width of the sidepanels 12 b, 12 c approximately 30 cm. Two spray nozzles 21 are disposedhorizontally at intervals on the side panel 12 a, and one spray nozzle21 on each of the side panels 12 b and 12 c. Note that these spraynozzles 21 are disposed at the same height.

The water supply mechanism 60 includes a liquid feed piping section 61and a liquid feed pump 62. The liquid feed piping section 61 connects awater source, not shown, such as a water line, and each spray nozzle 21to each other. The liquid feed piping section 61 includes a conductivepiping section 61 a (a metal piping section 61 a, in the presentembodiment) that is located on the upstream side of flow of water, andan insulating piping section 61 b (a resin piping section 61 b, in thepresent embodiment) that is located on the downstream of the same. Theliquid feed pump 62 feeds the water to each of the spray nozzles 21 viathe liquid feed piping section 61.

The air supply mechanism 70 includes an air feed pump 72 such as acompressor, and an air feed piping section 71. The air feed pipingsection 71 connects the air feed pump 72 and each of the spray nozzles21 to each other.

The charging mechanism 80 includes a charging power supply (ahigh-voltage power supply) 81, wiring sections 82, 83, and an outputregulator 84. The wiring section 82 connects a positive electrode of thecharging power supply 81 to a leading end portion of each spray nozzle21. The wiring section 83 connects a negative electrode of the chargingpower supply 81 to the conductive piping section 61 a of the liquid feedpiping section 61. This configuration positively charges the water(water drops) sprayed from the spray nozzle 21. The positive electrodeof the charging power supply 81 is grounded in such a manner that thespray nozzle 21 becomes a ground potential. The resin piping section 61b is made of electric insulating synthetic resin and is locateddownstream of the connection between the wiring section 83 and theliquid feed piping section 61. The output regulator 84 regulates anoutput of the charging power supply 81.

Although FIG. 1 shows a state in which the water supply mechanism 60,the air supply mechanism 70, and the charging mechanism 80 are connecteda single spray nozzle 21, and omits illustration of the other spraynozzles 21, the water supply mechanism 60, the air supply mechanism 70,and the charging mechanism 80 are connected to the other spray nozzles21 in the same manner as the one shown in FIG. 1. More specifically, forexample, the liquid feed piping section 61 of the water supply mechanism60 branches off in the middle, to be connected to the plurality of spraynozzles 21, and the air feed piping section 71 of the air supplymechanism 70 also branches off in the middle, to be connected to theplurality of spray nozzles 21. For instance, the plurality of spraynozzles 21 are connected in parallel to one another with respect to thecharging power supply 81 of the charging mechanism 80.

The outside air temperature sensor 18 is capable of detecting theoutside air temperature. For instance, when the outside air temperaturesensor 18 detects that the outside air temperature reaches apredetermined temperature or higher, the controller 16 determines thatthe load of the cooling operation exceeds a predetermined level setbeforehand, and then controls the liquid feed pump 62 and the air feedpump 72 to start spraying water from the plurality of spray nozzles 21.For example, during a predetermined time period, the controller 16controls the liquid feed pump 62 and the air feed pump 72 so that thewater is sprayed continuously or intermittently from each of the spraynozzles 21. The controller 16 also controls the output regulator 84 ofthe charging mechanism 80 and applies a voltage to each of the spraynozzles 21 by means of the charging power supply 81 in order toelectrically charge water drops sprayed from each of the spray nozzles21.

Next, the structure of the plurality of spray nozzles 21 is described indetail. In the present embodiment the plurality of spray nozzles 21 havestructures identical to one another. FIG. 3 is a cross-sectional diagramshowing one of the spray nozzles 21. As shown in FIG. 3, the spraynozzle 21 has a body 10, and an orifice 50 located downstream of thebody 10 (on the downstream side of the direction of water flow).

The body 10 functions to guide to the orifice 50 water supplied from thewater source, not shown, and to mix fine bubbles with the water suppliedto the body 10. The body 10 of the present embodiment extendsperpendicularly (vertically) and has the orifice 50 disposed downsidethereof. In other words, the body 10 of the present embodiment guides,downward, the water supplied from the water source that is not shown.The orifice 50 functions to receive the water that has bubbles mixedtherein by the body 10 and is guided to the orifice 50, stably feed thiswater mixed with bubbles to the outside of the spray nozzle 21, andexpand the bubbles discharged from the orifice by taking advantage ofthe difference in pressure between the front and back of the orifice, toproduce fine water drops to be sprayed.

The body 10 has a cylindrical contour with its axis longer than itsdiameter. In other words, the body 10 has a cylindrical contourextending perpendicularly. The body 10 has an air guide pipe (an outertubal portion) 31 with a pipe wall formed into the shape of a pipe, anda water guide pipe (an inner tubal portion) 41 that has a pipe wallformed into the shape of a pipe and is disposed on the inside of the airguide pipe 31. In other words, the water guide pipe 41 is inserted intothe air guide pipe 31.

The water guide pipe 41 is provided with a plurality of air introductionholes 43 a pierced through the pipe wall thereof in a thicknessdirection. The pipe wall of the air guide pipe 31 is provided with anair supply portion 32 for supplying air to an air flow path F1. The airsupply portion 32 has a cylindrical shape in which is formed an airsupply hole 32 a communicating with the air flow path F1. The air feedpiping section 71 shown in FIG. 1 is connected to this air supplyportion 32.

An axial direction of the air guide pipe 31 corresponds to that of thewater guide pipe 41. These axes are substantially aligned on the samestraight line. In other words, the air guide pipe 31 and the water guidepipe 41 are formed into a pipe extending perpendicularly and aredisposed in such a manner that the central axes thereof completely orroughly coincide with each other. The water guide pipe 41 has acylindrical shape with an inner diameter D1 and outer diameter D2. Theair guide pipe 31 has a cylindrical shape with an inner diameter D3, anouter diameter D4, and a length L1. The inner diameter D3 of the airguide pipe 31 is greater than the outer diameter D2 of the water guidepipe 41. An inner circumferential surface of the air guide pipe 31 andan outer circumferential surface of the water guide pipe 41 areseparated from each other in a radial direction.

One end of the air guide pipe 31 (a downstream end: a lower end, in thepresent embodiment) and one end of the water guide pipe 41 (a downstreamend: a lower end, in the present embodiment) are located atsubstantially the same position in the axial direction, and the otherend of the water guide pipe 41 (an upstream end: an upper end, in thepresent embodiment) is located upstream of the other end of the airguide pipe 31 (an upstream end: an upper end, in the presentembodiment). Specifically, the section near the other end of the waterguide pipe 41 projects from the other end of the air guide pipe 31 tothe upstream side. One end of the air flow path F1 (a lower end, in thepresent embodiment) is closed by the orifice 50, and the other end ofthe air flow path F1 (an upper end, in the present embodiment) is closedby a closing member 33.

The body 10 has an air guide portion 30, a water guide portion 40, and abubble formation portion 43. In the present embodiment, the water guideportion 40 corresponds to a water flow path F2 which is defined by aninner circumferential surface of the pipe wall of the water guide pipe41. The air guide portion 30 corresponds to the air flow path F1 whichis defined by the outer circumferential surface of the water guide pipe41 and an inner circumferential surface of the pipe wall of the airguide pipe 31. The bubble formation portion 43 has the plurality of airintroduction holes 43 a. The plurality of air introduction holes 43 aare disposed at intervals in the circumferential direction and axialdirection of the water guide pipe (the inner tubal portion) 41. The borediameter of each of the air introduction holes 43 a is smaller than thatof the supply hole 32 a of the air supply portion 32. The bubbleformation portion 43 of the water guide pipe 41 corresponds to acylindrical section between the air introduction hole 43 a located atthe uppermost stream and the air introduction hole 43 a located at thelowermost stream. In the present embodiment, the water guide portion 40guides, toward the orifice 50 disposed on the lower side of the body 10,water and air that is supplied from the air guide portion 30 into thewater guide portion 40 via each of the air introduction holes 43 a ofthe bubble formation portion 43 (i.e., water containing bubbles isguided perpendicularly downward). As a result, the water and the air(bubbles) are prevented from drifting as the water with bubbles in thewater guide portion 40 flows. This consequently provides a great rangeof stability conditions in which sufficiently fine water drops arestably sprayed from a spray portion 51 (i.e., a range in whichsufficiently fine water drops are stably sprayed remains wide even whenthe flow rates of the water and air supplied to the spray nozzle 21 arechanged).

The orifice 50 has the spray portion 51 that produces fine water dropsby expanding the bubbles by means of the difference in pressure betweenthe front and back of the orifice 50 and sprays the fine water drops,and a closing portion 52 for closing one end of the air flow path F1.The spray portion 51 of the present embodiment sprays the fine waterdrops downward.

The closing portion 52 is a ring-shaped area located radially outward,and the spray portion 51 is an area located radially inward of theclosing portion 52. The closing portion 52 has an inner surface (asurface on the upstream side) 52 a that comes into abutment with one endof the air guide pipe 31 and one end of the water guide pipe 41 to closethe end of the air flow path F1.

The spray portion 51 has a communication hole communicating with thewater flow path F2 and an external portion of the spray nozzle 21. Thecommunication hole includes a tapering hole 51 a with a taperingsurface, which has an inner diameter becoming smaller toward thedownstream side, and a spray hole 51 b that is located on the downstreamside of the tapering hole 51 a and sprays water. The distance betweenthe spray hole 51 b and the heat exchanger 13 and the bore diameter ofthe spray hole 51 b are set so that all or most of water drops sprayedfrom the spray hole 51 b evaporates (vaporizes) while moving toward theheat exchanger 13. The bore diameter of the spray hole 51 b is smallerthan that of the air introduction holes 43 a described hereinbelow.

The inner diameter of an upstream-side end portion of the tapering hole51 a is set to be approximately equal to or slightly smaller than theinner diameter D1 of one end of the water guide pipe 41. It is preferredthat the end of the water guide pipe 41 and the upstream-side endportion of the tapering hole 51 a be connected smoothly without adifference in height. An axial length of the tapering hole 51 a isgreater than an axial length L4 of the spray hole 51 b. Water that flowsthrough the tapering hole 51 a along the tapering surface toward thedownstream side reaches the spray hole 51 b, with the flow velocitythereof gradually increased. The water reaching the spray hole 51 bcontains a large number of fine bubbles and is sprayed to the outside ofthe spray nozzle 21 along with these bubbles. When or after the watercontaining a large number of bubbles is sprayed from the spray hole 51b, the bubbles expand and burst, creating fine water drops.

Each of the spray nozzle 21 of the present embodiment includes a supplyregion A1 provided with the air supply hole 32 a, a bubble formationregion A2 provided with the plurality of air introduction holes 43 a,and a guide region A3 for guiding to the spray portion 51 water thatcontains a large number of bubbles formed in the bubble formation regionA2. The guide region A3 of the present embodiment guides downward(specifically, toward the spray portion 51 provided on the lower side ofthe body 10) the water containing a large number of bubbles. The guideregion A3 also functions as a dispersion region (a mixing region) fordispersing a large number of bubbles in the water to some extent. Thisguide region A3 is located between the bubble formation region A2 andthe spray portion 51. The bubble formation region A2 is locateddownstream of the supply region A1. In other words, the supply regionA1, the bubble formation region A2, the guide region A3, and the sprayportion 51 are arranged axially in this order toward the downstreamside.

In the present embodiment, a length L2 of the bubble formation region A2is greater than the inner diameter D1 of the water guide pipe 41, in theaxial direction of the water guide pipe 41. Therefore, in a wide sectionin the axial direction, air is mixed into the water that flows throughthe water guide pipe 41. This can efficiently disperse and mix a largenumber of bubbles into the water. In addition, a length L3 of the guideregion A3 is greater than the inner diameter D1 of the water guide pipe41, in the axial direction of the water guide pipe 41. Therefore, thelarge number of bubbles mixed with the water in the bubble formationregion A2 can effectively be dispersed in the water in the guide regionA3.

Examples of the water source include a water line such as a water supplysystem. In this case, the liquid feed piping section 61 is connected toan upstream-side end portion of the water guide pipe 41. The liquid feedpiping section 61 is connected to a hydrant, not shown. The water issprayed from the spray nozzle 21 by driving the liquid feed pump 62 andthe air feed pump 72. It should be noted that the liquid feed pump 62can be omitted, and the water can be sprayed from the spray nozzle 21 byusing the water pressure of a water line. In this case, the cost forinstalling the liquid feed pump 62 and the running cost for driving theliquid feed pump 62 can be reduced. A tank with water pooled therein maybe used as the water source. In this case, the liquid feed pipingsection 61 is connected to a water inlet provided to the tank.

It is preferred that the average particle diameter of the water dropsbe, for example, 25 μm or less (it takes approximately 0.3 seconds orless for the water drops to evaporate). The average particle diameter ofthe water drops can be adjusted by adjusting the bore diameter of thespray hole 51 b, the bore diameter of the air introduction hole 43 a,the pressure applied to the water flow path F2, the pressure applied tothe air flow path F1, and the like.

It is preferred that the ratio between a water supply amount and an airsupply amount be, for example, 0.1 or less in weight ratio (weight ofair/weight of water). Power required to supply air can be made small byadjusting the weight ratio to this range. Because the conventionaltwo-fluid nozzle that injects air and water simultaneously from thespray hole creates fine water drops by adding shear force to the waterat the pressure of the air, the air needs to be injected at high speeds,requiring a weight ratio (weight of air/weight of water) of 0.4 or more.For this reason, the conventional two-fluid nozzle requires great powerto supply air.

Second Embodiment

FIG. 4 is a cross-sectional diagram showing a spray nozzle 21 of anoutdoor unit 11 according to a second embodiment of the presentinvention. The outdoor unit 11 according to the second embodiment isdifferent from the outdoor unit 11 of the first embodiment in terms ofthe structure of the spray nozzle 21. The same reference numerals asthose shown in FIG. 3 are applied to the components of the secondembodiment that are the same as those of the first embodiment, and hencedescriptions thereof are omitted accordingly.

As shown in FIG. 4, the spray nozzle 21 according to the secondembodiment has the supply region A1 provided with the air supply hole 32a, the bubble formation region A2, and the guide region A3 for guiding,to the spray portion 51, water containing a large number of bubblesformed in the bubble formation region A2, as with the first embodiment.

As shown in FIG. 4, the water guide pipe 41 is provided with the bubbleformation portion 43. The bubble formation portion 43 includes a porousportion 42 made of a porous material. The porous portion 42 is formedfrom, for example, foam metal. The porous portion 42 has a large numberof air introduction holes 43 a. The bubble formation portion 43corresponds to the region between the uppermost stream end of the porousportion 42 and the lowermost stream end of the same in the water guidepipe 41.

The porous portion 42 according to the present embodiment has acylindrical shape with substantially the same diameter as the otherparts of the water guide pipe 41; however, the shape of the porousportion 42 is not limited to a cylindrical shape. For instance, thewater guide pipe 41 may be provided with a plurality of porous portions42 that are disposed independently from each other in a scatteringmanner in a circumferential direction and/or a direction in which thewater guide pipe 41 extends.

The porous portion 42 has a large number of continuous pores (the largenumber of air introduction holes 43 a) configured by a series of pores.Therefore, air flowing through the air flow path F1 flows into the waterflow path F2 via the large number of air introduction holes 43 a. In thesecond embodiment, the presence of such porous portion 42 can make theporosity (void ratio) in the bubble formation region A2 greater thanthat of the first embodiment.

Third Embodiment

FIG. 5 is a cross-sectional diagram showing a spray nozzle 21 of anoutdoor unit 11 according to a third embodiment of the presentinvention. The outdoor unit 11 according to the third embodiment isdifferent from the outdoor unit 11 of the first embodiment in terms ofthe structure of the spray nozzle 21.

As shown in FIG. 5, the spray nozzle 21 according to the thirdembodiment includes the air guide portion 30, the water guide portion40, the bubble formation portion 43, and the spray portion 51. The waterguide portion 40 includes a cylindrical water guide pipe 44. The airguide portion 30 includes a cylindrical air guide pipe 34 connected to aside (pipe wall) of the water guide pipe 44. A leading end portion ofthe air guide pipe 34 is embedded in the water guide pipe 44. The sprayportion 51 is provided at a leading end portion (downstream-side endportion) of the water guide pipe 44.

The spray nozzle 21 has the air flow path F1 and the water flow path F2.The water flow path F2 is a space defined by an inner circumferentialsurface of the water guide pipe 44. The air flow path F1 is a spacedefined by an inner circumferential surface of the air guide pipe 34.The outer diameter of the air guide pipe 34 is smaller than the outerdiameter of the water guide pipe 44.

The spray portion 51 has a communication hole communicating with thewater flow path F2 and an external portion of the spray nozzle 21. Thecommunication hole includes the tapering hole 51 a with a taperingsurface, which has an inner diameter becoming smaller toward thedownstream side, and the spray hole 51 b that is located on thedownstream side of the tapering hole 51 a and sprays water to theoutside.

The air feed piping section 71 shown in FIG. 1 is connected to anupstream-side end portion of the air guide pipe 34, and the liquid feedpiping section 61 shown in FIG. 1 is connected to an upstream-side endportion of the water guide pipe 44. Air supplied from an air sourceflows through the air guide pipe 34 and is then introduced into waterthrough the plurality of air introduction holes 43 a, the water flowingthrough the water guide pipe 44.

FIG. 6A is a perspective view showing the air guide pipe 34 of the spraynozzle 21 according to the third embodiment. As shown in FIG. 6A, theair guide pipe 34 has a cylindrical shape with outer and inner diametersset to be substantially uniform in an axial direction.

The bubble formation portion 43 is located at the leading end portion ofthe air guide pipe 34. The bubble formation portion 43 is a circularplate-like body which is disposed in such a manner as to cover anopening of the leading end portion of the air guide pipe 34. Theplurality of air introduction holes 43 a are formed in a scatteringmanner throughout the entire area of this plate-like body. This bubbleformation portion 43 is disposed in the water flow path F2 of the waterguide pipe 44.

In this spray nozzle 21, air is blown out of the plurality of airintroduction holes 43 a of the bubble formation portion 43 in adirection that intersects with a direction in which the water flowsthrough the water flow path F2 (in a direction perpendicular to adirection of the water flow, in the present embodiment). According tosuch a configuration, the air blown out of the plurality of airintroduction holes 43 a can be made fine by shear force of the waterflow. As a result, finer bubbles can be produced as compared to a casewhere the air is blown out of the plurality of air introduction holes 43a toward the downstream side in a direction parallel to the direction ofthe water flow in the water flow path F2.

FIG. 6B is a perspective view showing modification 1 of the air guidepipe 34. In this modification 1, an upstream-side section of the airguide pipe 34 has a cylindrical shape with the outer and inner diametersset to be substantially uniform in the axial direction, and adownstream-side (leading end-side) section of the air guide pipe 34 hasa flare shape with the outer and inner diameters becoming largegradually toward the downstream side. The leading end portion of the airguide pipe 34 is provided with the bubble formation portion 43 havingthe plurality of air introduction holes 43 a.

Compared to the aspect shown in FIG. 6A, the area of the plate-likebubble formation portion 43 can be made greater than that illustrated inmodification 1 shown in FIG. 6B. Thus, when the number of airintroduction holes 43 a shown in FIG. 6A is same as that shown in FIG.6B, the space between the air introduction holes 43 a illustrated inmodification 1 can be made wider than that illustrated in the aspectshown in FIG. 6A, preventing reaggregation of the bubbles.

FIG. 6C is a perspective view showing modification 2 of the air guidepipe 34. In this modification 2, the air guide pipe 34 has a cylindricalshape with the outer and inner diameters set to be substantially uniformin the axial direction. The leading end portion of the air guide pipe 34is provided with the bubble formation portion 43. This bubble formationportion 43 is a porous body (porous portion) made of a porous material.The porous portion has the large number of air introduction holes 43 a.The porous body is formed from, for example, foam metal. The porous bodyhas a large number of continuous pores (the large number of airintroduction holes 43 a) configured by a series of pores. Inmodification 2, the presence of such porous portion can make theporosity (void ratio) in the bubble formation portion 43 greater thanthat illustrated in the aspects shown in FIGS. 6A and 6B.

As described above, in each of the embodiments, each spray nozzle 21 hasthe air guide portion 30 through which air flows, the water guideportion 40 through which water flows, the bubble formation portion 43that forms a large number of bubbles in the water by allowing the air ofthe air guide portion 30 to flow into the water of the water guideportion 40, and the spray portion 51 that is located downstream of thewater guide portion 40 in the direction of water flow and sprays, to theoutside, the water containing the large number of bubbles which is inthe water guide portion 40. Therefore, each of the embodiments canreduce the power of the entire air conditioning device while preventingcorrosion of the heat exchanger.

The first and second embodiments each employ the double pipe structurein which the air guide pipe 31 is disposed in such a manner as tosurround the outer circumference of the water guide pipe 41 providedwith one or more air introduction holes 43 a. Therefore, each of thespray nozzles 21 having the water guide portion 40, the air guideportion 30, and the bubble formation portion 43 can be producedinexpensively.

In the first and second embodiments, the plurality of air introductionholes 43 a are disposed at intervals in the circumferential direction ofthe water guide pipe 41 and the direction in which the water guide pipe41 extends. Therefore, unlike a configuration in which only one airintroduction hole 43 a is provided in the water guide pipe 41, the aircan be let flow into the water of the water guide pipe 41 from aplurality of sections that are disposed at intervals in thecircumferential direction and the direction in which the water guidepipe 41 extends. As a result, the water flowing through the water guidepipe 41 can have bubbles dispersed efficiently therein. In addition,compared to the configuration in which only one air introduction hole 43a is provided, the resistance for letting the air flow into the water issmaller, and the pressure required to let the air flow into the watercan be set lower, further reducing the power.

In the second embodiment, the porosity in the bubble formation portion43 can be increased because the bubble formation portion 43 includes theporous portion 42 with the plurality of air introduction holes 43 a.Such configuration can further reduce the resistance created when theair is introduced into the water of the water guide pipe 41 via thebubble formation portion 43. This can further reduce the pressurerequired to let the air flow into the water.

In the second embodiment, variations in bore diameter of the pluralityof air introduction holes (43 a) can be prevented by forming the porousportion 42 with foam metal, so that the diameter of bubbles to be formedin the bubble formation portion 43 can be made somewhat uniform,reducing variations in diameter of water drops sprayed by the sprayportion 51.

The third embodiment has the water guide pipe 44, and the air guide pipe34 that is connected to the water guide pipe 44 and has one or more airintroduction holes 43 a at the end portion thereof on the water guidepipe 44 side. The water guide portion 40 includes the water flow path F2defined by the inner circumferential surface of the water guide pipe 44.The air guide portion 30 has the air flow path F1 defined by the innercircumferential surface of the air guide pipe 34. The bubble formationportion 43 includes one or more air introduction holes 43 a. In thethird embodiment, the spray nozzle 21 can be configured with such asimple structure.

Each of the embodiments further has the charging mechanism 80 forelectrically charging the water sprayed from each spray nozzle 21. Eachof the water drops sprayed from the spray portion 51 moves through theair while being electrically charged. As a result, the water drops repeleach other with a force of electrostatic repulsion, preventingreaggregation of the water drops. This can also prevent an increase inwater drop diameters due to reaggregation. The electrostatic repulsionbetween the water drops can spread the water drops across a wide area.

In each of the embodiments, the water guide portion 40 vertically guidesthe water containing bubbles. Such configuration can prevent the waterand the air (bubbles) from drifting as the water with bubbles in thewater guide portion 40 flows. This consequently provides a great rangeof stability conditions in which sufficiently fine water drops arestably sprayed from the spray portion 51 (i.e., a range in whichsufficiently fine water drops are stably sprayed remains wide even whenthe flow rates of the water and air supplied to the spray nozzles 21 arechanged). In other words, when vertically guiding the water containingbubbles, such configuration can prevent the air (bubbles) from comingtogether on the upper side when the water containing the bubbles flowsthrough the water guide portion 40, and from flowing out of balancealong with the water (drifting), as in a case where the water containingthe bubbles is guided in another direction (i.e., horizontally).Consequently, even with different flow rates of the water and air orother conditions for supplying the water and air to the spray nozzles21, defective spray (where sufficiently fine water drops are notproduced or where the size of the water drops fluctuates, etc.) causeddue to the drift can be minimized on a wide scale. As a result,sufficiently fine water drops can stably be sprayed from the sprayportion 51.

Moreover, according to each of the embodiments, the water guide portion40 guides the water containing bubbles downward, and the spray portion51 sprays this water downward. Thus, compared to the configuration inwhich the water guide portion 40 guides the water containing bubbles ina different direction (e.g., upward or horizontally) and the sprayportion 51 sprays this water in the direction, the maximum range ofstability conditions (the water/air supply conditions in whichsufficiently fine water drops are stably sprayed from the spray portion51) can be obtained.

In addition, even when the water drops are large and cannot evaporateeasily, the spray portion 51 sprays such large water drops downward, andthe resultant force of the downward spray motion and gravity added tothe water drops cause the water drops to fall downward (e.g., onto theinstallation surface of the outdoor unit 11 or the like) acrosssubstantially the horizontal flow of air directed toward the heatexchanger 13. This configuration can prevent the heat exchanger 13 fromgetting wet by the large water drops.

Other Embodiments

The embodiments of the present invention are described above; however,the present invention is not limited to these embodiments and can bemodified and improved in various ways without departing from the scopeof the present invention.

Each of the embodiments describes the example in which the spray nozzles21 are disposed horizontally at intervals on the three side panels 12 a,12 b, 12 c facing the heat exchanger 13 so as to be able to spray waterdrops downward and to be at the same height, as shown in FIG. 2.However, the present invention is not limited to this configuration. Aslong as the cooling effect of the spray device 20 can be providedsubstantially uniformly to substantially the entire heat exchanger 13,the spray nozzles 21 may be disposed as shown in, for example, theoutdoor unit 11A of FIG. 7, so as to be able to spray water drops towardthe heat exchanger 13 (i.e., to spray water drops along the direction ofthe outside air flowing toward the heat exchanger 13). A specificexample of this configuration is described below.

Each of the spray nozzles 21 is disposed in such a manner as to spraywater drops toward the heat exchanger 13. In other words, each of thespray nozzles 21 is disposed, with an axial direction thereof beingdirected along the direction of the flow of air (air stream). The waterdrops sprayed from each spray nozzle 21 move toward the heat exchanger13 along the air stream direction while spreading radially. All or mostof the water drops vaporize prior to reaching the heat exchanger 13.

When disposing each of the spray nozzles 21 in the outdoor unit 11A insuch a manner as to spray water drops horizontally or slightly obliquelyas described above, it is preferred that the plurality of spray nozzles21 be disposed at intervals on the three side panels 12 a, 12 b, 12 cfacing the heat exchanger 13, as shown in FIG. 8. More specifically, theplurality of spray nozzles 21 are disposed vertically and horizontallyat an interval of, for example, several tens of centimeters in ascattering manner, based on the range in which the water drops from eachspray nozzle 21 are spread, i.e., the range in which the air flowingtoward the heat exchanger 13 is cooled by each spray nozzle 21. In thisarrangement example, the diameter of the range in which the water dropssprayed from each spray nozzle 21 are spread is approximately 50 cm, thewidth of the side panel 12 a approximately, for example, 100 cm, thewidth of the side panels 12 b, 12 c approximately 30 cm, and the heightof each side panel approximately 80 cm. Four spray nozzles 21 arearranged vertically and horizontally on the side panel 12 a, and twospray nozzles 21 a are arranged vertically on each of the side panels 12b and 12 c.

Arranging the spray nozzles 21 in this manner results in providing thecooling effect of the spray device 20 substantially uniformly tosubstantially the entire heat exchanger 13.

In a case where the spray nozzles 21 are disposed in such a manner as tospray water drops toward the heat exchanger 13 (i.e., along thedirection of outside air flowing toward the heat exchanger 13), theplurality of spray nozzles 21 may be disposed unevenly so that, forexample, a better cooling effect can be provided to some areas of theheat exchanger 13 than the other areas. A specific example of thisconfiguration is described below.

FIG. 9 is a schematic diagram for explaining another example of thearrangement of the spray nozzles 21 in relation to the heat exchanger13. The spray nozzles 21 are not shown in FIG. 9. The heat exchanger 13shown in FIG. 9 has three heat-transfer pipes P1, P2, P3. These threeheat-transfer pipes P1, P2, P3 each have an independent refrigerantpath. Each of the heat-transfer pipes has a refrigerant path thatmeanders through the heat exchanger 13, with a part bent at either endin a width direction of the heat exchanger 13. Each heat-transfer pipeis provided with a refrigerant inlet at its one end (a right end, inFIG. 9), and a refrigerant outlet at its other end (a left end, in FIG.9).

In order to change the refrigerant into supercooled liquid with apredetermined supercooling degree in the heat exchanger 13, it ispreferred that supercooling regions (downstream-side end regions) SB1,SB2, SB3 in the vicinity of the refrigerant outlets of the heat-transferpipes P1, P2, P3 be cooled intensively. In the arrangement example shownin FIG. 9, the plurality of spray nozzles 21 are disposed mainly at thepositions that face the supercooling regions SB1, SB2, SB3 in the heatexchanger 13.

Specific examples of disposing the spray nozzles 21 mainly in someregions include, for example, an aspect in which the plurality of spraynozzles 21 are disposed only at the positions facing the supercoolingregions SB1, SB2, SB3 in the heat exchanger 13, and an aspect in whichthe spray nozzles 21 are disposed more densely at the positions facingthe supercooling regions SB1, SB2, SB3 than at the positions facing theother regions.

In addition, for example, each of the spray nozzles 21 may be disposedin such a manner as to spray water drops upward, as shown in FIG. 10.

In this case, the spray nozzles 21 are disposed outside and below theheat exchanger 13 in the outdoor unit 11B. In this configuration, ineach spray nozzle 21 the water guide portion 40 guides the watercontaining bubbles upward, and the spray portion 51 sprays, upward, thiswater containing many bubbles which is guided by the water guide portion40. The plurality of spray nozzles 21 are disposed horizontally atintervals on the three side panels 12 a, 12 b, 12 c facing the heatexchanger 13, in such a manner as to spray water drops upward and to beat the same height (below the heat exchanger 13).

By allowing the water guide portion 40 to guide the water containingbubbles upward and allowing the spray portion 51 to spray this waterupward, the air and water are prevented from drifting as the water withbubbles in the water guide portion 40 flows, allowing the spray portion51 to stably spray sufficiently fine water drops.

Furthermore, because each spray nozzle 21 sprays the water drops upwardfrom below toward the outside air flowing toward the heat exchanger 13which has wind velocity distribution where the outside air accelerateson the upper side of the heat exchanger 13 (the wind velocitydistribution resulting from the positional relationship between the heatexchanger 13 and the fan 14), flight durations that are long enough forthe water drops to vaporize prior to reaching various sections of theheat exchanger 13 can be ensured as the water drops flow toward thevarious sections in a height direction of the heat exchanger 13. Thismechanism is described below specifically.

In the outdoor unit 11B in which the heat exchanger 13 is providedupright with respect to the installation surface (horizontal surface)and the fan 14 is disposed above and horizontally inward of the heatexchanger 13 in the case 2 (see FIG. 10), a wind velocity distributionshown in FIG. 11 is formed in which the air flows non-uniformly towardthe heat exchanger 13 and accelerates on the upper side of the heatexchanger 13. This is because the air suctioned through the air inlets(not shown) of the side panels 12 a, 12 b, 12 c of the case 2 flowsfaster near the fan 14 (the upper side). Note that the horizontal arrowsdirected toward the heat exchanger 13 indicate flows of the outside air(air) formed as a result of discharging the air of the outdoor unit 11B(the case 2) to the outside by means of the fan 14 (see the upwardarrows in FIG. 11), the outside air flowing toward the heat exchanger13. The lengths of the arrows showing these flows of air represent thewind velocities in the corresponding height positions.

In this state, when each spray nozzle 21 sprays the water drops upwardfrom below the heat exchanger 13, the distance between the spray nozzle21 below the heat exchanger 13 and the upper part of the heat exchanger13 increases. As a result, the flight durations that are long enough forthe droplets to vaporize can be ensured, the droplets being the waterdrops sprayed from the spray nozzle 21 and flowing toward the upper partof the heat exchanger 13 (see the arrow a in FIG. 11). Therefore,despite the fast flow of the outside air flowing toward the upper partof the heat exchanger 13, the water drops can vaporize prior to reachingthe upper part of the heat exchanger 13. On the other hand, although thedistance between the spray nozzle 21 disposed below the heat exchanger13 and the lower part of the heat exchanger 13 is short, the fact thatthe air flows slowly toward this section of the heat exchanger 13 canensure the flight durations that are long enough for the water drops toevaporate, the water drops being sprayed from the spray nozzle 21 andflowing toward the lower part of the heat exchanger 13 (see the arrow (3in FIG. 11). Consequently, the water drops can vaporize prior toreaching the lower part of the heat exchanger 13. As described above, inthe outdoor unit 11B, the positional relationship between the heatexchanger 13 and the fan 14 creates the wind velocity distribution wherethe air flowing toward the heat exchanger 13 is faster at the upper sidethereof. In such a configuration where the water drops are sprayedupward from below the heat exchanger 13, the distance between the spraynozzle 21 and the heat exchanger 13 in which the water drops travel tothe heat exchanger 13 is longer toward the height positions of the heatexchanger 13 where the air flows at higher velocities, and the distancebetween the spray nozzle 21 and the heat exchanger 13 in which the waterdrops travel to the heat exchanger 13 is shorter toward the heightpositions of the heat exchanger 13 where the air flows at lowervelocities. Owing to this configuration, the flight durations longenough for the water drops to vaporize can be ensured. Consequently, thewater drops sprayed from the spray nozzle 21 vaporize prior to reachingthe heat exchanger 13, resulting in preventing the heat exchanger 13from getting wet by the water drops sprayed from the spray nozzle 21.

In each of the embodiments, each spray nozzle 21 is so shaped as toallow the entire water guide portion 40 to guide water vertically;however, the shape of the spray nozzle 21 is not limited thereto. Inother words, each spray nozzle 21 may be configured to allow a sectioncorresponding at least to the guide region A3 of the water guide portion40 to guide water vertically (downward, in each of the embodiments). Forexample, in the water guide portion 40 described in each embodiment, asection downstream of at least the bubble formation portion 43 (to bemore specific, a section of the water guide pipe 41 that is downstreamof the lowermost stream air introduction hole 43 a) may guide at least,vertically, the water containing bubbles toward the spray portion 51.This configuration can effectively prevent the air and the water fromdrifting as the water with bubbles in the water guide portion 40 flows,and stably spray sufficiently fine water drops from the spray portion51.

In each of the embodiments, an electric current is applied to the watersupplied from the water supply mechanism 60 (electrifying the water) asshown in FIG. 1, to charge the water sprayed from the spray device 20.However, the mechanism of electrically charging the water is not limitedthereto. For example, the water to be sprayed may be charged by means ofstatic induction, as shown in FIGS. 12A and 12B, or by dischargingelectricity in the air, as shown in FIG. 13. This mechanism is describedbelow specifically.

First of all, the method of using static induction is described withreference to FIGS. 12A and 12B. FIG. 12A is a schematic diagram forexplaining modification 1 of a charging mechanism 80, and FIG. 12B anenlarged perspective view for explaining one of the spray nozzles 21 andan induction electrode 85.

The liquid feed piping section 61 of the water supply mechanism 60 ofthe spray device 20 does not have to be provided with the insulatingpiping section 61 b described in the embodiments. In other words, theentire liquid feed piping section 61 is formed from a conductive member.It should be noted that, in the liquid feed piping section 61, at leastthe region between the spray nozzle 21 and the section connected to anelectrode of the charging power supply 81 may be formed from aconductive member, and, for example, the upstream part of the sectionconnected to the electrode may be formed from an insulating member.

The charging mechanism 80 has the charging power supply 81 and theinduction electrode 85. The charging power supply 81 has one of itselectrodes connected to the spray nozzle 21, and the other one to theinduction electrode 85. The charging power supply 81 can therefore applya voltage between the spray nozzle 21 and the induction electrode 85. Inthe present embodiment, the positive electrode is connected to the spraynozzle 21, and the negative electrode to the induction electrode 85.Therefore, the water (water drops) sprayed from the spray nozzle 21 ischarged positively. The positive electrode of the charging power supply81 is grounded such that the spray nozzle 21 becomes the groundpotential.

The induction electrode 85 is disposed with a predetermined distancefrom the spray nozzle 21, and generates static induction in waterpassing through the spray nozzle 21, by means of a predetermined voltageapplied between the induction electrode 85 and the spray nozzle 21. Morespecifically, the induction electrode 85 is an annular electrode with aninner diameter larger than an outer diameter of the spray nozzle 21 (seeFIG. 12B). This induction electrode 85 is disposed at the leading end ofthe spray nozzle 21 in the axial direction of the spray nozzle 21 or ata position slightly close to the base end of the spray nozzle 21 withrespect to the leading end, in such a manner that a central axis of theinduction electrode 85 matches the axis (central axis) of the spraynozzle 21. The induction electrode 85 may be disposed in front of thespray nozzle 21 (toward the heat exchanger) in the axial direction ofthe spray nozzle 21. However, in view of the possibility ofcontamination of the induction electrode 85 by the mist-like watersprayed from the spray nozzle 21, it is preferred that the inductionelectrode 85 be disposed at the leading end of the spray nozzle 21 or atthe position slightly close to the base end with respect to the leadingend, as described above.

In this charging mechanism 80, the charging power supply 81 applies apredetermined voltage (e.g., 5000 V to 10000 V) between the spray nozzle21 and the induction electrode 85, and thereby static induction isgenerated in the water passing through the spray nozzle 21. The water inthis state is sprayed from the spray nozzle 21, charging the resultantwater drops.

Next is described, with reference to FIG. 13, the method of dischargingelectricity to charge the water to be sprayed. FIG. 13 is a schematicdiagram for explaining modification 2 of the charging mechanism 80.

As with the flow path portion of the static induction method, the liquidfeed piping section 61 of the water supply mechanism 60 of the spraydevice 20 in this method does not have to be provided with theinsulating piping section described in the embodiments.

The charging mechanism 80 has the charging power supply 81 and a pair ofdischarge electrodes (a first discharge electrode 86 and a seconddischarge electrode 87).

The charging power supply 81 has the positive electrode thereofconnected to the first discharge electrode 86 and the negative electrodeto the second discharge electrode 87. The negative electrode is groundedsuch that the second discharge electrode 87 becomes the groundpotential. The charging power supply 81 therefore can apply a voltagebetween the first discharge electrode 86 and the second dischargeelectrode 87 (between the pair of discharge electrodes).

The pair of discharge electrodes 86, 87 is disposed in such a manner asto sandwich a region through which the mist-like water sprayed from thespray nozzle 21 passes.

In this charging mechanism 80, the charging power supply 81 applies apredetermined voltage (e.g., 5000 V to 10000 V) between the pair of thedischarge electrodes 86, 87, and thereby a discharge (e.g., a coronadischarge) is generated between the discharge electrodes 86, 87. Due tothis discharge, the water drops passing between the discharge electrodes86, 87 are charged. In this case, the water drops are chargedpositively.

In the charging mechanism (the charging mechanism in the method ofelectrifying the water) 80 according to each embodiment, the waterflowing through the insulating piping section 61 b is electrified due tothe application of a voltage between the spray nozzle 21 and the metalpiping section 61 a, with the insulating piping section 61 btherebetween, as shown in FIG. 1. As a result, the water to be sprayedbecomes charged, but the position to electrify the water is not limitedto the insulating piping section 61 b. For instance, when the watersupply mechanism 60 is provided with a water source such as a tank,water pooled in this water source may be electrified to charge thewater, and the charged water may be supplied to the spray nozzle. Thisis a method of charging water through electrification, but in this casethe water guide pipe of the water supply mechanism does not have to beprovided with the insulating piping section.

Each of the embodiments describes the example in which the spray device20 has the charging mechanism 80 as a charger; however, the charger isnot a required component in the present invention and therefore can beomitted. In case of omitting the charger, the resin piping section 61 bis not required, so the entire liquid feed piping section 61 can beformed using the metal piping section 61 a.

The first and second embodiments each describe the example of providingthe guide region A3 between the bubble formation region A2 and the sprayportion 51; however, the guide region A3 can be omitted. In such a case,the air introduction holes 43 a can be formed in the vicinity of thetapering hole 51 a of the water guide pipe 41. However, in the aspect inwhich the guide region A3 is provided as shown in FIG. 3, the largenumber of bubbles mixed in the water can be dispersed in the water moreeasily than when the guide region A3 is not provided. Thus, more uniformwater drops can be sprayed from the spray portion 51.

Each of the embodiments illustrates the example of positioning the fan14 downstream of the heat exchanger 13 in the direction of the airflow.However, the present invention is not limited to this configuration. Forexample, the fan 14, the spray nozzles 21, and the heat exchanger 13 maybe disposed in this order toward the downstream side in the direction ofthe airflow.

The second and third embodiments each describe the example of formingthe porous portion 42 with foam metal. However, the present invention isnot limited to this configuration. The porous portion 42 may notnecessarily be formed from metal but can be formed from, for example,synthetic resin.

The third embodiment illustrates the situation where the air guide pipe(the second guide pipe) 34 is connected to a side of the water guidepipe (the first guide pipe) 44. However, the present invention is notlimited to this configuration. For instance, the air guide pipe 34 maybe connected to a longitudinal end portion (upstream-side end portion)of the water guide pipe 44. In this case, the direction in which thewater guide pipe 44 extends is substantially the same as the directionin which the air guide pipe 34 extends.

The embodiments are summarized hereinbelow.

(1) According to each of the embodiments, the present invention canreduce the power of the entire air conditioning device while preventingcorrosion of the heat exchanger thereof. This mechanism is describedhereinafter specifically.

In other words, in each of the embodiments, water containing a largenumber of bubbles are formed in the water guide portion (40), and thiswater containing a large number of bubbles is sprayed from the sprayportion (51). When or after the water containing bubbles is sprayed fromthe spray portion (51), the bubbles burst, creating fine droplets. Thuscreated fine droplets easily vaporize (evaporate) prior to reaching theheat exchanger (13), preventing adherence of the droplets to the heatexchanger (13). In this manner, corrosion of the heat exchanger (13) isprevented.

Once the droplets vaporize prior to reaching the heat exchanger (13),the air flowing toward the heat exchanger (13) is cooled by its latentheat (vaporization heat). Therefore, because the temperature of the airpassing through the heat exchanger (13) becomes lower than that obtainedwhen the water is not sprayed, the power required to drive thecompressor, the fan and the like at the time of the cooling operation ofthe air conditioning device can be reduced. Moreover, in the presentconfiguration, no large power is required to spray air to water at highspeeds through the injection hole of the spray nozzle, as seen in theconventional two-fluid nozzle. In other words, because the presentconfiguration only requires power for forming a large number of bubblesin the water flowing through the water guide portion (40), the amount ofair required is lower than that of the conventional nozzle, enabling tomake the power required to feed air lower than that required in theconventional nozzle. This configuration can effectively reduce the powerof the entire air conditioning device.

(2) In the outdoor unit, as an example, the water guide portion (40) hasa pipe wall shaped into a pipe, and also has one or more airintroduction holes (43 a) penetrating the pipe wall in the thicknessdirection. The air guide portion (30) is shaped into a pipe so as tosurround the outer circumference of the water guide portion (40).

According to this configuration, each spray nozzle (21) can be producedat low costs by adopting the double pipe structure in which the airguide portion (30) is disposed so as to surround the outer circumferenceof the water guide portion (40) provided with one or more airintroduction holes (43 a).

(3) In the outdoor unit, it is preferred that the water guide portion(40) have the plurality of air introduction holes (43 a) and that theplurality of air introduction holes (43 a) be disposed at intervals inthe circumferential direction of the water guide portion (40) and thedirection in which the water guide portion (40) extends.

According to this configuration, because the plurality of airintroduction holes (43 a) are provided at intervals in thecircumferential direction of the water guide portion (40) and thedirection in which the water guide portion (40) extends, the air can belet flow into the water of the water guide portion (40) through theplurality of intervals provided in the circumferential direction and thedirection in which the water guide portion (40) extends, unlike aconfiguration having one air introduction hole (43 a). Therefore, thebubbles can efficiently be dispersed in the water flowing through thewater guide portion (40). In addition, the resistance for letting theair flow in the water becomes smaller than that obtained in theconfiguration having one air introduction hole (43 a), enabling to lowerthe pressure required to let the air flow into the water. As a result,the power can further be reduced.

(4) In the outdoor unit, the water guide portion (40) may be shaped intoa pipe and have, at least partially, the porous portion (42), and theair guide portion (30) may be shaped into a pipe so as to surround theouter circumference of the water guide portion (40).

According to this configuration, because the water guide portion (40)has the porous portion (42), the bubbles can have a uniform diameter,reducing variations in diameter of droplets sprayed by the spray portion(51).

(5) In the outdoor unit, the porous portion (42) is formed from foammetal.

According to this configuration, the porous portion (42) is formed fromfoam metal. Owing to a large porosity of the porous portion (42), theresistance that is generated when introducing the air into the water ofthe water guide pipe (41) through the porous portion (42) can bereduced. As a result, the pressure required to let the air flow into thewater can be lowered.

(6) In the outdoor unit, the water guide portion (40) may be shaped intoa pipe. The air guide portion (30) may also be shaped into a pipe andhave a leading end portion thereof connected to the water guide portion(40).

According to this configuration, each of the spray nozzles 21 can beconfigured with a simple structure in which the air guide portion (30)is connected to the water guide portion (40).

(7) In the outdoor unit, it is preferred that the air guide portion (30)have the porous portion (42) at the leading end portion thereof.

According to this configuration, because the air guide portion (30) hasthe porous portion (42), the bubbles can have a uniform diameter,reducing variations in diameter of droplets sprayed by the spray portion(51).

(8) It is preferred that the outdoor unit further have a charger (80)for electrically charging the water sprayed from the spray nozzle (21).

According to this configuration, the droplets to be sprayed from thespray portion (51) move through the air while being charged. This meansthat the droplets repel each other with a force of electrostaticrepulsion, preventing reaggregation of the droplets. This can alsoprevent an increase in droplet diameters due to reaggregation. Theelectrostatic repulsion between the droplets can spread the dropletsacross a wide area.

(9) In the outdoor unit (11) of the air conditioning device, it ispreferred that the water guide portion (40) vertically guide the watercontaining bubbles.

In such an aspect where the water guide portion (40) vertically guidesthe water containing bubbles, the water and the air (bubbles) areprevented from drifting as the water with bubbles in the water guideportion (40) flows. This consequently provides a great range ofstability conditions in which sufficiently fine droplets are stablysprayed from the spray portion (51). In other words, a range in whichsufficiently fine droplets are stably sprayed remains wide even when theflow rates of the water and air supplied to the spray nozzle (21) arechanged. Specifically, when perpendicularly guiding the water containingbubbles, the above-described configuration can prevent the air (bubbles)from coming together on the upper side when the water containing thebubbles flows through the water guide portion (40), and then flowing outof balance along with the water (drifting), as in a case where the watercontaining bubbles is guided in another direction (i.e., horizontally).Consequently, even with different flow rates of the water and air orother conditions for supplying the water and air to the spray nozzle(21), defective spray (where sufficiently fine droplets are not producedor where the size of the droplets fluctuates, etc.) caused due to thedrift can be minimized on a wide scale. As a result, sufficiently finedroplets can stably be sprayed from the spray portion (51).

(10) In such a case where the guide water portion (40) vertically guidesthe water containing bubbles, it is preferred that the spray nozzle (21)be disposed outside the heat exchanger (13) in the outdoor unit (11),that the water guide portion (40) guide the water containing bubblesdownward, and that the spray portion (51) be disposed on the lower sideof the water guide portion (40) and spray, downward, the watercontaining a large number of bubbles that is guided by the water guideportion (40).

Compared to a configuration in which the water guide portion (40) guidesthe water containing bubbles in a different direction (e.g., upward orhorizontally) and the spray portion (51) sprays this water in thedirection, allowing the water guide portion (40) to guide the watercontaining bubbles downward and the spray portion (51) to spray thiswater downward can provide the maximum range of stability conditions. Inother words, this configuration can realize the maximum range ofwater/air supply conditions in which sufficiently fine droplets arestably sprayed from the spray portion (51).

Moreover, because even large droplets are sprayed downward from thespray portion (51), these large droplets are dropped across asubstantially horizontal flow of air directed toward the heat exchanger(13) by the force of spray and gravity added to these droplets.Therefore, even when large droplets are sprayed, this configuration canprevent adherence of the large droplets to the heat exchanger (13),whereby the heat exchanger (13) is prevented from being wet

(11) When the water guide portion (40) vertically guides the watercontaining bubbles, the outdoor unit (11) may have the fan (14) thatforms flow of air directed toward the heat exchanger (13), wherein thefan (14) is disposed above and inward of the heat exchanger (13) in theoutdoor unit (11) and discharges upward, to the outside of the outdoorunit (11), air that has flowed into the outdoor unit (11) and beensubjected to heat exchange by the heat exchanger (13), the spray nozzle(21) is disposed further toward an outer side than the heat exchanger(13) in the outdoor unit (11), the water guide portion (40) guides thewater containing bubbles upward, and wherein the spray portion (51) isdisposed on the upper side of the water guide portion (40) and spraysupward the water containing a large number of bubbles that is guided bythe water guide portion (40).

By allowing the water guide portion (40) to guide the water containingbubbles upward and allowing the spray portion (51) to spray this waterupward, the air and water are prevented from drifting as the water withbubbles in the water guide portion (40) flows, allowing the sprayportion (51) to stably spray sufficiently fine droplets.

In addition, because the spray nozzle (21) sprays droplets upward withrespect to the flow of air directed toward the heat exchanger (13), theflow of air having a wind velocity distribution where the airaccelerates on the upper side of the heat exchanger (13) (the windvelocity distribution resulting from the positional relationship betweenthe heat exchanger (13) and the fan (14): see FIG. 11), flight durationsthat are long enough for the droplets to vaporize prior to reachingvarious sections of the heat exchanger (13) can be ensured, the dropletsflowing toward the various sections in a height direction of the heatexchanger (13). Such a configuration can prevent the heat exchanger (13)from getting wet by the droplets. This mechanism is describedhereinbelow specifically.

The distance between the spray nozzle (21) below the heat exchanger (13)and the upper part of the heat exchanger (13) increases. As a result,flight durations that are long enough for the droplets to vaporize canbe ensured as the droplets are sprayed from the spray nozzle (21) andflow toward the upper part of the heat exchanger (13). Therefore,despite the fast flow of the air flowing toward the upper part of theheat exchanger (13), the droplets can vaporize prior to reaching theupper part of the heat exchanger (13). On the other hand, although thedistance between the spray nozzle (21) below the heat exchanger (13) andthe lower part of the heat exchanger (13) is short, the fact that theair flows slowly toward this section can ensure the flight durationsthat are long enough for the droplets to vaporize as the droplets aresprayed from the spray nozzle (21) and flow toward the lower part of theheat exchanger (13). Consequently, the water drops can vaporize prior toreaching the lower part of the heat exchanger (13). As described above,in the outdoor unit (11), the positional relationship between the heatexchanger (13) and the fan (14) creates the wind velocity distributionwhere the air flowing toward the heat exchanger (13) is faster at theupper side thereof. In such a configuration where the droplets aresprayed upward from the spray nozzle (21), the distance between thespray nozzle (21) and the heat exchanger (13) in which the dropletstravel to the heat exchanger (13) becomes longer toward the heightpositions of the heat exchanger (13) where the air flows at highervelocities, and the distance between the spray nozzle (21) and the heatexchanger (13) in which the droplets travel to the heat exchanger (13)becomes shorter toward the height positions of the heat exchanger (13)where the air flows at lower velocities. Owing to this configuration,the flight durations long enough for the droplets to vaporize can beensured. Consequently, the droplets sprayed from the spray nozzle (21)vaporize prior to reaching the heat exchanger (13), resulting inpreventing the heat exchanger (13) from getting wet by the dropletssprayed from the spray nozzle (21).

As described above, each of the embodiments can reduce the power of theentire air conditioning device while preventing corrosion of the heatexchanger thereof.

EXPLANATION OF REFERENCE NUMERALS

-   -   11, 11A, 11B Outdoor unit    -   13 Heat exchanger    -   20 Spray device    -   21 Spray nozzle    -   30 Air guide portion    -   31 Air guide pipe    -   34 Air guide pipe (second guide pipe)    -   40 Water guide portion    -   41 Water guide pipe    -   42 Porous body    -   44 Water guide pipe (first guide pipe)    -   50 Orifice    -   51 Spray portion    -   80 Charger

1. An outdoor unit for an air conditioning device, comprising: a heatexchanger; and a spray nozzle for spraying water to air flowing towardthe heat exchanger, wherein the spray nozzle has: an air guide portionthrough which air flows; a water guide portion through which water flowsand which causes the air flowing through the air guide portion to flowinto water to form water containing a large number of bubbles; and aspray portion that is located downstream of the water guide portion in adirection of water flow and sprays, to the outside, the water containinga large number of bubbles which is formed in the water guide portion. 2.The outdoor unit for an air conditioning device according to claim 1,wherein the water guide portion has a pipe wall shaped into a pipe andalso has one or a plurality of air introduction holes penetrating thepipe wall in a thickness direction, and the air guide portion is shapedinto a pipe so as to surround an outer circumference of the water guideportion.
 3. The outdoor unit for an air conditioning device according toclaim 2, wherein the water guide portion has the plurality of airintroduction holes, and the plurality of air introduction holes areprovided at intervals in a circumferential direction of the water guideportion and a direction in which the water guide portion extends.
 4. Theoutdoor unit for an air conditioning device according to claim 1,wherein the water guide portion is shaped into a pipe and has, at leastpartially, a porous portion, and the air guide portion is shaped into apipe so as to surround an outer circumference of the water guideportion.
 5. The outdoor unit for an air conditioning device according toclaim 4, wherein the porous portion is formed from foam metal.
 6. Theoutdoor unit for an air conditioning device according to claim 1,wherein the water guide portion is shaped into a pipe, and the air guideportion is shaped into a pipe and has a leading end portion thereofconnected to the water guide portion.
 7. The outdoor unit for an airconditioning device according to claim 6, wherein the air guide portionhas a porous portion at a leading end portion thereof.
 8. The outdoorunit for an air conditioning device according to claim 1, furthercomprising: a charger that electrically charges water sprayed from thespray nozzle.
 9. The outdoor unit for an air conditioning deviceaccording to claim 1, wherein the water guide portion vertically guideswater containing bubbles.
 10. The outdoor unit for an air conditioningdevice according to claim 9, wherein the spray nozzle is disposedoutside the heat exchanger in the outdoor unit, the water guide portionguides water containing bubbles downward, and the spray portion isdisposed on a lower side of the water guide portion and sprays,downward, the water containing a large number of bubbles which is guidedby the water guide portion.
 11. The outdoor unit for an air conditioningdevice according to claim 9, further comprising: a fan that forms flowof air directed toward the heat exchanger, wherein the fan is disposedabove and inward of the heat exchanger in the outdoor unit anddischarges upward, to the outside of the outdoor unit, air that hasflowed into the outdoor unit and been subjected to heat exchange by theheat exchanger, the spray nozzle is disposed further toward an outerside than the heat exchanger in the outdoor unit, the water guideportion guides water containing bubbles upward, and the spray portion isdisposed on an upper side of the water guide portion and sprays upwardthe water containing a large number of bubbles which is guided by thewater guide portion.